Jerusalem (AFP) - Israeli police questioned Prime Minister Benjamin Netanyahu and his wife for several hours on Friday over corruption allegations that threaten the right-wing premier's long tenure.

The questioning, the eighth such session since 2017, came after police last month recommended Netanyahu's indictment in two graft cases.

"The Prime Minister and his wife were questioned for a number of hours as part of an investigation," a police spokesman said in a statement without giving more details.

Israeli media said the five-hour grilling related to allegations Netanyahu sought a deal with Shaul Elovitch, the controlling shareholder of telecoms group Bezeq, which would have seen Netanyahu receive good press on Elovitch's Walla! news website in exchange for business concessions.

Netanyahu, 68, has denied all charges and rejected talk of stepping down. He is due to meet US President Donald Trump, perhaps his closest international ally, at the White House on Monday.

"I am sure that there will be nothing and I want to tell millions of Israelis that the extraordinary show of support me, my wife and my family have received is heartwarming," he said in a video posted on Facebook after the questioning.

He added he was looking forward to meeting Trump, who he called a "true friend of Israel."

An AFP journalist saw police arriving at Netanyahu's official Jerusalem residence in two vehicles at around 9 am (0700 GMT).

His wife Sara was questioned at the national fraud squad headquarters near Tel Aviv, media said.

Elovitch and Nir Hefetz, a former media adviser to the Netanyahu family, were among seven suspects arrested last week as fraud suspicions against Netanyahu snowballed.

- New arrest reported -

In addition, Israeli army radio said Friday that "a former senior communications ministry official close to the prime minister was detained this morning for questioning in the Bezeq affair."

The former official was not named.

Channel 10 News reported on Thursday evening that police have seen text conversations between Sara Netanyahu and Elovitch's wife Iris which strengthen suspicions that their husbands traded favours.

Iris Elovitch and the couple's son Or were among the seven suspects rounded up last week.

She was released from custody to house arrest Monday and Or Elovitch was freed on bail, police said.

A statement issued after the broadcast by advisers to Netanyahu branded the report "fake news."

"No such things ever occurred," it said in Hebrew. "Tendentious and lying leaks against Mrs. Netanyahu are intended to hurt the prime minister and the Likud government."

Hefetz is alleged to have acted as a messenger between Netanyahu and Bezeq and Walla! bosses.

He is also suspected of trying to bribe a retired judge to block a probe into the prime minister's wife over alleged misuse of public funds.

Public radio said on Friday that both were being questioned at fraud squad headquarters simultaneously with Sara Netanyahu but separately.

Police have now questioned the premier eight times since the beginning of 2017, and last month said there was sufficient evidence to charge him with graft, fraud and breach of trust in two other cases.

In one, Netanyahu and family members are suspected of receiving one million shekels ($285,000, 230,000 euros) of luxury cigars, champagne and jewellery from wealthy figures in exchange for financial or personal favours.

In the other case, investigators suspect the premier of trying to reach an agreement with the owner of Yediot Aharonot, a top Israeli daily newspaper, for more favourable coverage.

Israeli media said police would question him on the Bezeq affair for the first time on Friday and would also take from him a statement as a witness in suspected corruption around Israel's purchase of three submarines from German industrial giant ThyssenKrupp.

The cases have fuelled speculation he could be forced to step down or call an early election, but Netanyahu says he is innocent of any wrongdoing.

The other parties in his right-wing coalition government have so far stood by him.

Eli Kamir, another former Netanyahu adviser arrested last week, was on Wednesday released from police custody but placed under house arrest.

Shlomo Filber, a Netanyahu ally for more than 20 years and former director general of the communications ministry, was freed last week after agreeing to turn state's witness in exchange for avoiding jail, police said.

He is suspected of mediating between Netanyahu and Elovitch and promoting regulatory changes worth millions to Bezeq.